With further development of the network, the user bandwidth is increased at a high speed. Operators find that in many core application scenes, capacity and slots of a single router can no longer meet business demands. Super core nodes actually become a bottleneck of further business development for telecommunication operators. As a network cluster system, the router provides High Available (HA) data transmission for telecommunication operators, thus the router is required to be HA and expandable.
An exchange plane of the existing router equipment adopts single-stage exchange, and a router cluster equipment is composed of a Cluster Central Chassis (CCC) and a Cluster Line-card Chassis (CLC). The existing router cluster equipment adopts a three-stage Clos structure, and achieves a three-stage exchange mechanism, where the first stage and the third stage exchange are performed in the CLC, and the CCC finishes the second stage exchange among chassis. In the management plane of the existing router cluster equipment, each CLC is connected with a CCC via two links (two links forming an active/standby relationship) to form a data channel, and via the data channel, the CCC manages the CLC, processes and delivers related routing.
A router cluster is also called a router matrix or multi-chassis interconnection (Multi-Chassis). Simply speaking, multiple routers are interconnected to form a logically integrated router system. The generation of the cluster technology has two direct reasons: Firstly, capacity of a single machine has gradually developed to a limit; secondly, due to the generation of super nodes, the network structure is increasingly complicated and maintenance and management are more difficult.
The objective of introducing the cluster technology to the router field is to connect two or more common core routers in a certain manner, so that the core routers can perform cooperative work and parallel processing among equipments. Therefore, smooth expansion of system capacity is achieved, and the routers appear as just one logical router when viewed from outside. Users hope to expand capacity and slots of certain nodes without affecting original equipment services, and to form a router cluster equipment to meet a higher capacity of the users, that is, it is required to realize smooth expansion. In the prior art, if the CLC and the CCC need to act as a set of cluster equipment, the expansion process is performed when services are not running. Cables between the CCC and the CLC should be connected, configurations should be done on the two equipments, and finally a set of cluster is formed through restarting.
In the prior art, no matter adding a CLC or a CCC, the equipment expansion is performed when CLC services are interrupted, while smooth expansion cannot be performed without interrupting the data services.